A conventional TFT-LCD (Thin Film Transistor-Liquid Crystal Display) is formed by assembling a TFT array substrate and a color filter substrate.
Recently, a Color Filter On Array (COA) technology, in which a color filter layer is formed on the array substrate after the completion of the TFT array fabrication, is developed. That is to say, in the COA technology, the color filter layer is formed on the array substrate. Because of accurate wiring, it is not necessary to increase a width of a light-shielding layer in view of cell-assembling process in the COA technology, so that a higher transmittance can be obtained. The COA technology, in which the color filter layer is integrated into the array substrate, has attracted more and more attentions because its advantages of lower fabricating cost, smaller thickness, smaller weight and the like.
However, the conventional COA technology requires many masks, resulted in complicated fabrication process, high cost, and difficult to guarantee the product quality for complicated fabrication process.